Walker’s call for the governor’s resignation is particularly significant since he was one of Greitens’ earliest supporters. In a Facebook post, Walker said the situation “will make it impossible to lead the state going forward.”

Former Missouri GOP chairman Ed Martin also called for Greitens to step down on his talk radio show on AM 1380 Tuesday afternoon, saying “the people deserve better.”

Greitens’ spokesman didn’t immediately respond to a request for comment.

A longtime GOP operative in the state told TPM that, based on his conversations with sources in the State House, he expects the number of Republicans calling for the governor to step down will be “up to 10 trickling in through the day.”

“I think there’s a lot of unease and uncertainty about what’s next,” said the operative, who asked to speak on background because he is lobbying for several bills currently being considered by the legislature. “I think people are believing that there’s more things to come out—that if he did tie her up, the likelihood of another incident or something, in their minds, is higher.”

Greitens is accused of tying the woman to a piece of exercise equipment in the basement of his home and taking a nude photograph of her, then threatening to leak the photo if she went public about the affair. And the woman’s ex-husband has said she told him that in a separate July 2015 incident first reported by TPM, Greitens slapped the woman after she told him she’d slept with her husband.

Per the woman’s request, her identity has not been made public.

Greitens acknowledged last week that he engaged in an extramarital affair, but has denied the blackmail and slapping allegations.

“The current scandal is believable given all the other stuff that’s gone on, the way he treats the press, the way he treats other Republican lawmakers,” Dave Robertson, head of the political science department at the University of Missouri-St. Louis, told TPM.

The Missouri Republican operative told TPM that GOP members of the state’s House of Representatives will meet Tuesday afternoon to discuss next steps, and are leaning towards launching their own investigation into Greitens’ alleged behavior.

City of St. Louis Circuit Attorney Kim Gardner announced last week that she had launched a criminal probe. Al Watkins, an attorney for the woman’s ex-husband, told TPM he’d been contacted by Gardner’s office and the FBI. Watkins told CNN Monday that he’d provided law enforcement with some five hours of private audio recordings made in which the woman told her then-husband about her sexual encounters with Greitens.

As he tries to ride out the scandal, Greitens is finding his position weakened by his lack of close relationships in Jefferson City, and by several pre-existing controversies that dogged his gubernatorial campaign and his first year in office.

The former NAVY Seal, Rhodes Scholar and bestselling author campaigned as a pro-transparency, anti-establishment family man who would clean up corruption in Missouri politics. But questions about his own ethics surfaced before he was even sworn in.

Greitens made use of the donor list for a veterans’ charity he founded, The Mission Continues, during his campaign, ultimately paying a $100 fine for failing to initially report the list as an in-kind contribution. He also broke with tradition by failing to disclose the amount of donations he received for his inaugural celebrations.

Once he took office, the transparency-related scandals kept coming. Greitens’ campaign treasurer founded a nonprofit group, A New Missouri, that promotes the governor’s legislative agenda but is not required to reveal who is contributing or how much. And in December, Republican Attorney General Josh Hawley launched an investigation into Greitens’ and some of his staffers’ use of a messaging app that deletes messages after they’re read.

“He was Mr. Ethics and Mr. Transparency as a candidate and once he gets in office he sings a different tune and behaves differently,” Smith added. “So he’s being held to account for that.”

Separately, the governor has come under fire for his aggressive effort to appoint five new members to the eight-member State Board of Education, and to orchestrate the firing of education commissioner Margie Vandeven.

Smith, the professor, called the school board fight the “biggest issue so far” in Greitens’ tenure.

“He’s tried to blow up the process and it just hasn’t gone down very well,” he said. “Everybody gets that the governor has an agenda. But he’s basically saying ‘I’m going to bypass the Missouri Constitution here to get my agenda accomplished.’ There are people in Jefferson City who are saying, ‘or not.’”

“This happened not that long ago so he was cruising for a really rough time I think with the Missouri legislature because of that, and then these allegations compound it,” Smith added.

The GOP operative told TPM that Greitens had failed to establish one-on-one relationships with the lawmakers who now hold his political future in their hands.

“Republicans do not know him,” the source said. “There’s no relationship—when I say that I mean many lawmakers had not spoken to the governor personally ‘til he started calling the other day.”

Greitens and his wife, Sheena, made a round of calls to GOP lawmakers last week insisting that no further allegations would come out.

The governor has also reportedly reached out to donors professing his commitment to remaining in office. He has made no public appearances since the scandal broke and enlisted his lawyer to handle the press fallout.

The GOP operative said this may be too little, too late.

“It’s all very controlled and tight,” the source said. “There’s no leadership meeting of the type lawmakers are used to in which the governor might say, ‘Hey I want to tell you what’s happening,’ and there’s some give-and-take. Now there’s just a statement from the lawyer and that’s it.”